Hydration is key in summer heat

Last year, New York’s first documented heat-related death occurred July 8, after three consecutive days with the temperature at 90 degrees or above. The victim was a 57-year-old man on Staten Island. The summer before, a record-breaking eight-day heat wave killed four people, three of them with health problems.

Experts say these deaths can nearly always be averted by taking simple precautions.

Summer heat waves are becoming more frequent and increasingly intense. They put young and old, the physically active and the sedentary, at risk of a heat-related illness and death.

New York is among cities that have taken steps to mitigate the risk by planting trees, making surfaces like roofs more reflective and opening air-conditioned centers where people can go to cool off. Former Mayor Michael R. Bloomberg’s Million Trees program is two years ahead of schedule, with 2015 the expected completion date.

Prevention starts with preparation. While being properly hydrated is always important, it can be lifesaving in summer heat. The bigger you are, the more time you spend outdoors and the more intensely you exercise, the more you should drink.

Don’t rely on thirst to tell you how much. A liter or two of water is needed to replace what is lost through sweat and respiration; some salt may also be needed, especially for people exerting themselves.

Normally salted food is adequate, but if you sweat heavily or exercise in the heat for prolonged periods, consider a sports drink diluted by half with water (because most commercial sports drinks contain too much salt). Do not take salt tablets.

Before engaging in vigorous activity in hot weather, give yourself a week or more to become acclimated. Start with moderate exercise for short periods, and then build up slowly over eight to 10 days to more strenuous or prolonged activity.

Heat illness is a leading cause of death and disability among high school athletes, with the highest rate among football players, according to the Centers for Disease Control and Prevention.

Preseason football practice typically starts during the hottest, most humid summer days, when players are least physically fit and most prone to collapse. Although the National Athletic Trainers’ Association has guidelines on the duration and intensity of summer practices and the gear to be used, coaches often neglect to follow them.

A player who becomes confused, disoriented or unsteady should be removed from practice to a cooler environment, fanned, rehydrated and doused with or immersed in cool water.

Remove the athlete’s clothing or soak it with water, which conducts heat away from the body much more effectively than air.

If the player’s core temperature (the most accurate measurement is rectal) rises to 104 degrees or higher, it’s considered a medical emergency.

Call 911 and immerse the player in ice water while waiting for an ambulance, according to revised guidelines issued last week by the trainers’ association, which emphasize, “Cool first, transport second.”

A body temperature of 105 degrees for more than 30 minutes can be fatal, noted Douglas Casa, the director of athletic training at the University of Connecticut.

When the rectal temperature drops to 102, cut back on cooling to keep the person from shivering, which will produce more heat, but keep monitoring body temperature.

While the player is being cooled, vigorously massage the arms and legs to propel cooled blood back to the body’s core, where heat causes the worst damage.

Even if a heat-exhausted player recovers quickly, he should not return to vigorous activity that day.

“A player may say, ‘I feel better now,’ but that doesn’t mean it’s safe to go back in the game,” said Dr. Christopher B. Colwell, the director of emergency medicine at Denver Health Medical Center. “The way someone feels doesn’t necessarily reflect the body’s core temperature, which could still be seriously elevated.”

People who work in hot settings can also face heat illness. Farm workers have a substantially higher risk for heat-related deaths than other workers. Others at risk include those who work outdoors (road crews and construction workers, for example), firefighters, and workers in bakeries, boiler rooms, factories and mines.

Workers at greatest risk include people ages 65 and older, and those who are overweight or have heart disease or high blood pressure or take medications like beta blockers that reduce sweating and raise heat sensitivity.

The CDC recommends that workers in hot settings wear light-colored, breathable clothing; schedule heavy work for the coolest parts of the day; take frequent breaks in the shade or a cool area; drink water often; and avoid drinks with caffeine, alcohol or lots of sugar.

Special attention to older adults, the physically handicapped and people with chronic physical or mental illness is critical when the air temperature soars. Colwell urges relatives, friends or neighbors to check in with such people daily.

Older adults with cognitive issues may be unable to accurately report symptoms over the phone, so twice-a-day visits may be necessary to check for signs of heat exhaustion and assure that they are drinking plenty of cool beverages.

Frequent showers or tepid baths can help keep body temperature normal, but an older or handicapped person may need assistance to do this safely.

It need not be very hot for older adults or the chronically ill to succumb, Colwell said. If their homes do not have air-conditioning, he suggests installing fans, and if they are unable to go out on their own, he suggests taking them to a movie theater, indoor mall, supermarket, public library or cooling center in midday.

But if their home is cool, they are best off staying indoors on hot days and avoiding exertion.